On my way home from work tonight my tranny started slipping. 2 miles from home at the end of a 40 mile drive I stopped at a stop sign, and she didn't want to get moving again. At first I thought the wheels were just spinning as the roads were a bit iffy, but once I got going and onto dry road, it became clear that the power just wasn't making it from the engine to the wheels.

Babied it home, and I'm convinced that it's a classic low tranny fluid situation. Specifically, it acts like the torque converter just staying full enough to do its job. Rev up ridiculously high, and it moves and keeps moving. Stop, and she doesn't want to go again.

First concern is putting new fluid in. Just want to double check. I believe the right stuff to use is ATF+4 since +3 is discontinued. Next concern is how much to buy.

First action in the morning is to just get it two miles down the road to the shop to have it looked at. I'm comfortable "wasting" some fluid to make that drive.

Next concern is that this came on all at once with no warning whatsoever. Must have sprung a leak somewhere. It was 100% fine taking off from the stop sign 3 miles before... No offroading, no craziness, just a casual drive home at about 45 mph on mostly clear gravel roads.

What should I look at first when the sun comes up? I'm thinking cooler lines, cooler, etc... Any other likely suspects?

I'd appreciate any words of wisdom. I really need to have this thing road worthy by 3PM tomorrow.

 

Check it for obvious leaks of course first and fore most. Second I would replace the fluid AND filter. Also, how long has it been since your last band adjustment. This could be in the cards, I don't deal much with transmissions so I take it to a shop to so a band adjustment, but typically the high price places cost around $180 for a band adjustment.

This sounds like whats in the cards for you to start off with to ensure your transmission isn't needing to be replaced.

And yes, ATF +4 is what goes in the transmission pan.

 

assuming you hvae the 5.2/5.9 everything white widow said is correct, if you have the 4.7 just ignore the part about band adjustment, that transmission does not have bands.

specifically check the seal on the trans pan, and the lines running to the cooler.

 

What kind of vehicle do you have?


Brian

 

No codes pop up? IIRC, I had a code P0750: LR solenoid circuit. Had the same symptoms. Hi revs and very slow go.

 

Haven't had a chance to check for codes just yet. Have an appointment to get it looked it in about 20 minutes here. Hope it makes it, I'd rather not add fluid before I go, just so the mechanic can see the actual symptoms while they're happening.

LR solenoid? What does "LR" stand for? Oh, and how big of a job did it end up being getting that fixed?

And, yes, I forgot to mention which vehicle it is. Oops... It's a 98 with the 5.9.

 

You are lucky the job may just involve band adjustments and fluid/filter change. My problem went away on its own but I'm still looking out for it. LR solenoid has something to do with Low Reverse solenoid in the tranny valve body. It manages the Low gear and reverse gear.

 

Went away on its own? Hmm...

Just drove it up to the shop, and the tranny seemed to be operating normally. I didn't want to push my luck and get on the gas real hard or anything, but driving gently all seemed to be well during the 2 or 3 mile drive.

Low gear and reverse gear... Yep, those are the ones that were acting funny last night...

EDIT: Shop just called, said it ran fine for them on their test drive also. Fluid was full, but smells burnt (which I could have guessed). They wanted to do a flush. Asked them to drain, fill, and replace filter instead. I like the idea of having a new filter, and also like the idea that the mechanic will actually get a chance to look inside the pan for any obvious trouble signs. Will have to go back for a band adjustment in a day or two. I need the truck back in 2 hours to go to work (don't like the idea of putting that off, but it's just the way it's gotta be today). The guy who called didn't know if he had checked for codes.

Makes me nervous. I don't like problems that "just go away". They have a tendency of "just coming back" at the worst possible time.

 

A lot of people are probably going to ring in momentarliy and "VERY STRONGLY DISCOURAGE" flushing.....I would definitely go with the fluid and filter change and band asjustment if necessary but not too many good stories about flushing.... obviously you have to determine the source of the leak but fluid/filter change should be a good head start. ATF+4 should be backwards compatible with ATF+3 BUT NOT THE OTHER WAY AROUND....meaing you should be able to put ATF+4 in +3 transmissions.

 

Just an update...

Drove it to work and back, about a 75 mile round trip. Intentionally took a good mixture of roads. Highways, city driving, and gravel. No problems at all. Got a little bold on the way home and got into the gas pedal pretty hard a few times on gravel. Tires spun, truck fishtailed, everything seemed normal. Tranny was definitely running strong.

Since the fluid was full, I'm not worried about looking for leaks.

Given the information I have now, I'm most strongly suspecting the solenoid that was mentioned. It affects the gears that were having problems, and best explains why it ran fine again in the morning. I figure a stuck solenoid could easily be broken loose again when everything cooled down and contracted.